A number of methods for preparing 1,3,4-benzotriazepine-2-ones have been described in the literature. In general, the compounds are prepared by either of two methods from a 2-aminobenzophenone. In the first method the 2-aminobenzophenone is treated with semicarbazide to give an aminobenzophenone semicarbazone. This product is cyclized to give the benzotriazepine-2-one. See Bull. Chem. Soc. Jap. 43, 135-138 (1970); Japanese publications 70 11,148 (CA73:25544a) and 70 11,147 (CA73:25545b). Alternately, a 2-aminobenzophenone hydrazone is treated with phosgene to give the desired benzotriazepine-2-one. See U.S. Pat. No. 3,176,008; J. Pharm. Sci. 63(6), 838-41 (1974); and J. Med. Chem. 7(3), 386 (1964). Despite the reported central nervous system activity of the 1,3,4-benzotriazepine-2-ones, the thio analogues are unknown and no satisfactory method for their preparation has been described in the literature.